Add-ins bring your favorite apps right inside Outlook, so you can accomplish tasks quickly without needing to switch back and forth between email and other apps. Add-ins are a great way to increase usage of your apps by making them accessible directly within Outlook. Last year, we announced the rollout of add-ins to Outlook 2016 for Mac in Office Insider. We are now making add-ins available to all Outlook 2016 for Mac customers who have Exchange 2013 Service Pack 1 or higher, or Office 365 or Outlook.com mailboxes. See the full post here.